Cleanup: remove ARG CACHEBUST from Dockerfiles

Clean up: remove debug lines, restore health endpoint

Fix: copy Dockerfile.hf to Dockerfile for HF build

feat: HF Spaces deployment - single container with Piper + LibreTranslate

feat: Piper TTS + backend translate/tts endpoints, Docker Compose with LibreTranslate sidecar

feat: add Docker support + fix __init__.py config import